1. Field of the Invention
The present invention relates to a transfer printing method and a transfer printing system for printing images on a workpiece, and more particularly, to a transfer printing method and a transfer printing system for printing images on a workpiece with supercritical fluid.
2. Description of the Prior Art
With the rise of environmental protection awareness, the relevant regulations are getting stricter. In order to meet requirements of the environmental protection and the relevant regulations, surface decorating technology has been developed with a trend to free-spraying or using hydro-paint. For example, a conventional heat transfer printing method is used for transferring a decorating pattern on a plastic film onto a surface of product, so as to decorate the product. However, a temperature of the conventional heat transfer printing method needs to be raised over glass transition temperature (Tg) so as to soften the plastic film. In such a manner, it will cause power consumption and time wasting. In addition, it will be confined to plasticity of the plastic film. As a result, the product can not meet appearance requirement of an arc shape. Furthermore, if the product is made of thermoplastic material, the conventional transfer printing method will cause heat deformation during transferring process. Hence, design of a transfer printing method for satisfying environmental protection regulations and for design flexibility is an important issue of the product appearance design.